Preparation And Functional Identification Of Monoclonal Antibody Against Guertu Virus

Guertu virus（GTV）is a tick-borne bunyavirus closely related to the human disease associated viruses,Severe fever with thrombocytopenia syndrome virus（SFTSV）and Heartland virus（HRTV）,which belongs to the genus Bandavirus in the Phenuiviridae family.In vitro and in vivo studies of GTV have showed that it is a potential viral pathogen that poses significant threats to healthcare and public health.Therefore,it is necessary to prepare for the early diagnosis and drug development of GTV in order to prevent and control the potential risks in the future.The viral glycoprotein（GP）is the main antigen that induces host to produce neutralizing antibodies,and is an important target for the development of neutralizing monoclonal antibodies（m Abs）.Because of their high viral nucleoprotein（NP）expression in infected cells and host,they are considered detection targets for confirmed infections.This study aims to prepare neutralizing m Abs targeting GTV-GP and m Abs targeting GTV-NP by using hybridoma cell fusion technology and to identify their functions.The three neutralizing m Abs have cross-reaction and cross-neutralization activities for GTV,SFTSV,and HRTV.It is speculated that the three viruses have the same spatial domain through antigenic epitope analysis.These three antibodies may have similar virus inhibition mechanisms which are candidate materials for the development of broad-spectrum antiviral drugs.Four of the eight m Abs（22G1,25C2,25E2 and 26F8）targeting GTV-NP could recognize the linear epitope of GTV-NP and showed cross-reactivity to SFTSV-NP,but not to HRTV.Two fine epitopes E_NP1 and E_NP2 recognized were identified,which are highly conserved in NPs of GTV and SFTSV,but specific in HRTV-NP.The characteristics of antigenic epitopes are further analyzed,and the differences in the properties of antigenic epitopes for the differences in the mechanism of action of antibodies and their effects on virus Potential functional impact of infection,and replication.The NP-specific monoclonal antibody prepared in this study will provide materials and a theoretical basis for the development of viral antigen detection methods for GTV and SFTSV.